of the larger foraminae. As the
name 'laminal' indicates, it is this surface which in the fresh state is
covered by the sensitive laminae.

_The Inferior or Plantar Surface_, hollowed in the form of a low arch,
presents for our inspection two regions, an anterior and a posterior,
divided by a well-marked line, the _Semilunar Crest_, which extends forward
in the shape of a semicircle. The anterior region, as is the laminal
surface, is covered with foraminae; in this case more minute. In the recent
state it is covered by the sensitive sole. The posterior region, lying
immediately behind the semilunar crest, shows on each side of a median
process a large foramen, the _Plantar Foramen_. From this foramen runs the
_Plantar Groove_, a channel, bounded above by the superior edge, and below
by the semilunar crest of the bone, which conducts the plantar arteries
into the _Semilunar Sinus_, a well-marked cavity in the interior of the
bone.

_The Superior or Articular Surface_ consists of two shallow depressions,
divided by a slight median ridge. Its posterior part shows a transversely
elongated facet for articulation with the navicular bone.

_The Superior Edge_, outlining the superior margin of the laminal surface,
describes a curve, with the convexity of the curve forward. In the centre
of the curve is a triangular process, the _Pyramidal Process_, which serves
as the point of attachment of the extensor pedis.

_The Inferior Edge_, the most extensive of the three, separates the laminal
from the solar surface. It is semicircular in shape, sharp, and finely
dentated, and is perforated by eight to ten large foraminae.

_The Posterior Edge_, very slightly concave, divides the small,
transversely elongated facet of the superior surface from the posterior
region of the inferior surface.

_The Lateral Angles_ of the bone, also termed the _Wings_, are two
projections directed backwards. Each is divided by a cleft into an upper,
the _Basilar Process_, and a lower, the _Retrossal Process_. In old animals
the posterior portion of the cleft separating the two processes gradually
becomes filled in with bony deposit, thus transforming the cleft into a
foramen, which gives passage to the preplantar artery. We may mention
in passing that the lateral angles give attachment to the lateral
fibro-cartilages, and that the lateral angles themselves in old horses
become increased in size owing to ossification of portions of the adjacent
latera